Method of neutralizing acid treated oils



Oct- 4, 1932- H. H. CANNON METHOD OF NEUTRALIZING ACID TREATED OILS Filed July s, i929 ,n NOE HUGH HARLEY CANmN 7U /NV 70H ATTORNEY Patented Oct. 4, 1932 r l, narran stares P'Araur ortica nuez-i r-rAnLRY CANNON, or Los ANGELES, CALIFORNIA, AssreNoR To CANNON-PRUTZ- MAN rRnATINe PROCESSES, LTD., OR Los ANGELES, OALIFORNIA, A CORPORATION or voALiroRNIA,

METHOD OF NEUTRALIZING- ACID TREATED OILS j Application filed July 8, 1929. SerialvNo. 376,517.

r .The primary object of my inventionk is-to neutralize petroleum oils which have been treated with Ysulfuric acid, a more expeditious and economical manner than has heretofore been possible." 4

YAn `object of my invention is to avoid the Y use of aqueous alkaline solutions or the ad.-

dition of any water to the oil.

An object of my invention' is to use solely dry pulverulent reagentscapable of at once neutralizing.l and -absorbing the acidic constituents of the oil and which, after they have performed these functions,may be freely iltered out.

, vMy invention is adapted particularly to the neutralizationof acid treated gasolines, kerosenes, cracked naphthas and other volatile and nonviscous products of petroleum, but .inasmuch as it isalso suitable, under some circumstances, for the neutralization of more viscous petroleum products, such as lubricating oils, and of acid treated shale oils and coal tar products, I do not restrict the scope of my invention to the volatile products first "y named. i v Y I eifect this` neutralization in the following manner, which is illustrated in the ow Vdiagrams Figs. 1 and 2 of the attached drawing, in which e Fig. 1 illustrates the steps taken when neu- 4tralization is to be effected without any treatstep.

kment of` the-oil between the neutralizing step and the fina-l 'filtration step; and

Fig. 2 illustrates the steps taken when an vadsorbent clay is applied to the oil between the neutralization step and the filtration ;As my neutralizing methodv is substantiallyl continuous (it'may be made entirely so by providing certain elements of theapparatus in duplicate) it is quite important `that thegacid oil come to the neutralization step in, acondition approaching constancyas regards degree of acidity andv freedom from Y acidtar.v I thereforeprefer to treat aiow l y stream of thefoil continuously, the acid dose being accurately proportioned to the volume vof the oil stream, and to separate the acid sludge from the-acidied oil in continuous apparatus.

A suggested method for acid treating is l sludge-free oil passes through apipe to the neutralizer 21.' f The sludge separator above referred to is the subject of my copending application entitled Apparatus for separating sludge,

4Serial No. 340,383, filed February 16, 1929.

Otherwise the apparatus and the method described are well known and I do not claim them, the description 4being illustrative only. Nor do I restrict my invention to this nor toi any other specific methodI of acid treating the oil. The only purpose in the use of continuous apparatus for treating and desludg- `ing is to reduce the amount of labor required for manipulating and regulating the` neutralizing apparatus proper. Good .results ymay be had in neutralizing oil treated in batches, particularly if the sludge be drawn olf and the `oil thereafter mixed and kept in gentle motion while feeding to the neutralizer.

Referring again to Fig. 1 of the drawing, 22 and 23 are feed hoppers or any of the well known devices for feeding measured quantities of dry powders, these hoppers or measuring devices being arranged to introduce the reagent materials into the top of neutralizer 21. A pump 24 having a suction pipe 25 and a discharge pipe 26 controlled by valve 27 withdraws a mixture of oil and reagent powder from the bottom of the neutralizer and returns it over the top, thus keeping the contents of the neutralizer in suspension. This circulation should be performed at a relatively rapid rate, and if preferred the, pump may take suction from below the liquid level in the upper portion lof the .tank'and return into the bottom.

A branch pipe 28 controlled by a valve 29 admits a portion of this circulating Yow to v a vertical'tubular (or'any other) filter press 30. A pipe 3l controlled by valve 32'per-4 mitsa Yportion of the suspension vfed to Vthe press to returnt'o'rthetopjof the neutralz'er..

A part of thesolids contained in. the filter,AV

y feed stream is deposited insidethe filtering tube 33 rwhile a corresponding quantity kof clarified neutralized oil is discharged through pipe 34 to a place of storage or disposal not shown. Y-

:In manipulating this apparatus pump 24' "is adjusted in speed to 'maintain the desired rapidity of circulation `through the neutralviz er,v'alve 32 is adjusted to'ffmaintain'thedesired rapidity 'of circulation vthrough the press, and valve 27is adjusted from timeto time to 7maintain andfto increase the'pressure f within theA press. Valve 29 is a stop Yvalve vonly and is. normally wide open; 'Y

' `|lhe neutralization ofthe `acid oilisfef- -fected by time contact of theoil with a -mixtureV of powdered reagent '.materials... This mixture consists essentially of an .alkaline material, capable of f neutralizing Vsulfuric -andsulfonic acids, with` an absorbent-mate f rial, capable o ffa'bs'orbing 'into its pores any Y y finely disseminated ac id'sludgeas lwell as 4the salts 'resulting from rthe chemical neutralization. Ther absorbent material may Y also bean adsorbent, but is inotnecessarilyl so, my y preferred material being diatoma-Y ceous earth jwhich has practically no adsorp- 'f tive properties as regards coloringlmatter or other 4 impurities in '.solutionf-'in petroleum andsimilaroils i I Whereit is desirable or necessary to give theoil a ybleaching treatment with an aol-V sorbent such as jbleachingclay l prefer 'to givefthis?,treatmentin asep'arate step, fol.-

1 lowingthe neutralization proper, asgwill be hereinafter described. Y

a specific alkaline i reagent I prefer to' use sodiumcarbonate (commercial soda iash),

y which is bothcheapand leEectivm-though it Yis'possibleto use any ofthe alkali hydrates or carbonates orfof the alkali-earthliydrates. The latter, though eje'c'tive neutralizing agents,'have a tendency to retard .filtration 'and krequire excessiveV proportionsof the absorbent earth; sodium hydrate vis difficult to reduce to lthe required degree of comniinution,fand the other materialsnamed are more J costly, but' all `of `these may be useful under appropriate conditions. l c

.Asa specificabsorbentffmaterial I prefer to use `a sinceou's earth, known commercially as diatomaceous earth, infusorial earth and I.kieselguhr..A The lightest'.andinosty porous Y 'o lgrades are moreleconomical than the cheaper 'and more yearthy varieties, andi a` calcined earth fis to be preferred to awraw earth.

' e Lightand highly porous clays or magnesian mineral'sare also suited`v tothev purposes ofV my invention, though less so thanthesili-r ceous earths.'

The v quantity o f the alkaline agent required in any specific case cannot be reduced to a general figure.` Obviously/vit will vary Adirectly with the acidityof the Oil, and itjWill also vary inversely with the time of contact,

with the reactivity of the alkali usedand with the'degreeof comminution of the alkali, because reaction takesplace only on the` surface of a solid particle.- VAs the'treatment is a continuousrone itis quite sucient for all `purposes of operative control to start feeding an c excessief alkali and togradually cut down the dosage tothe point where the press effluent shows signs of going over tothe acid'side. The test shouldbe appliedto Ythe presseflluent and vnot to the contents ofthe neutralizer,

which will usually be slightly acid.

The purpose of the absorbent earth is a dual one. ttakes up mechanically andwith-- draws Vfrom contact with the alkali the minute particles of sludge which` pass through .the most effective sludge .separating apparatus 'and which, if `.neutralized in contact'with the oil, tend Vto become oil-solubleand to cause discoloration of the flnalproduotmlt also attaches 'and' draws into its a pores grains or flakes or certain reaction lproducts which, if

allowedto remain freely suspended in-the oil, tend' to clog the' filter cakea'ndfrender ltrationxtedious and difficult. a

i-The quantity of absorbent earth'required Y varies over Va wide range with thenature of the earth,the alkaliV and the oil.v When using sodiumcarbonate and a high grade of siliceous earth, a weight of earth Yequalto one- VVtenth'the weight of the alkali is usually suf- *I ficient. lf the much heavier aluminous clays i are used the weight required may be from` half the weightk ofthe" alkali to an.V equal weight. The rule inppractice is to useV the lsmallest quantity of earth consistent withrobtainingr asV press effluent a brilliant oil, and

with maintaining the free 'filtering proper-V ties of the cake. .lf the flow rate-through the filter is, or becomes, too low before the pressV i is sufficiently filled, the-difficulty may in al- Y most all cases be corrected by feeding a larger proportion of earth. An excess of earth is never harmful except as it is wasteful.

It has been stated that these two materials i should be in the form of dry powders, but 'the word'- .dry may notv be Ataken to Vmeank anhydrous. A desirable state of dryness is'that at which each of the powders is entirely Vincoherent, andthisphysical condition is conymal Vwater Ycontent ofthe earth is available for supplyingY water which maybe required for the reaction between acidic constituents and dry-alkali, and in manycases the'reac` toninay be accelerated and results improved sistent with the presence inthe alkali'of from i 2% to 5% of water and in the diatomaeeous earth.r of as much as 15% of'water.. The norofcoherence; A greater vquantity will ren` der the filter cake impermeable.

y VIt is important thatthe alkali and theearth befed to the neutralizing vessel simultaneously. They may,as a matterof convenience and'proper control, be mixed in advance in the desired` proportion and fed into the oil in a single stream. The sameresults kare had,

'with rather less convenience, by feeding two properlyv proportioned separate streams. They may evenbe added in alternate separatedoses, provided' only, that each dose be of such .small quantity as not seriously to alter the ratio-between earth alkali: oil in the neutralizing vessel. In other words, the feed should be substantially but need not be strich ly continuous and simultaneous. i

In case it is desired to treat the neutralized oil with clay or other adsorbent I make a suitable addition to the above described process. Referringto Fig` 2, thedrawing and the description are' the same as above, up to and in cluding the circulating pump 24and its suction pipe 25, discharge pipe 26 and control valve 27, Pipe' 26, however, branches into a pipe leading into the medial portion of a Y Y substantially closed se tlingVv tank 36, having preferably a conical'bottom. In this tank the bulk of the spent reagent subsides to a layer of slush indicated at 37, leaving a layer of relatively clear oil indicated at 38. rllliis oil flows forward through a pipe 39 controlled by a valve 40 into a clay mixing tank 4l which is provided with a feed hopper (or equivalent device) 42 for measuring and .introducingv v the clay;

From the bottom of the mixer a pipe 42 provided'with a valve 43 leads to the suction ofv a pump 44 which discharges through a `pipe 45 into a filter 46. The clay-containing oil is circulated rapidly through the. filtering Ytube 47, returning to the mixer through ai pipe 48 having a pressure controlling valve 49. In passing through the tube under pressure a part of the'liquid constituent passes through the wall of the tube and flows from the effluent pipe 50 as a Vneutralized and purilied oil. rlhe cake of clay containing some spentreagent which accumulates in the tube is discharged at intervals in the usual manner.

By providing filter presses in duplicate this operation, like the foregoing, may be made strictly continuous.

The layer of spent reagent and oil slush which collects in the bottom of settling tank ,36 may be withdrawn by opening drain valve 5l in pipe 52. rIhis is unduly wasteful of oil and I prefer to provide a branchpipe 53 having` a'valve 54 and communicating with the suction of pump 44. Through this pipe the slush may be pumped, at suitable intervals, into the saine filter press. If the clay sired it is better to precoat the press cloth vwith clay and finish filling the press with reagent fromV the slush. effects a substantially complete recovery of oil from the spent reagent without any extraneous operation orl apparatus.

rlhe'essence of my invention lies in simultaneously treating an acid ified oil with a solid alkaline powder and a solid absorbent powder. lffhen these reagents are applied in this manner their action is complementary, the absorbent taking up the sludge particles `which would otherwise be neutralized by the alkali and thus preventing the resolution of sludge in the oil and also acting as an absorbent for alkali reaction products and as a filter aid, while the alkali neutralizes the dissolved acid bodies and ensures complete neutrality, which is difficult to obtain by the use of the absorbent alone. rlhe combined reagent isniucli more effecting and economical than either use1 separately or than the twoapplied seriatum.

IWhen applied in a continuous process, as above described, my invention lies in the following steps z-(a) in providing a owstream of acidified oil from which as much as possible of the acid and sludge has previously been removed (t) in feeding into this stream a mixed or double reagent composed of a solid powdered alkaline material and a solid powdered absorbent material, the feed of the two materials being substantially constant and substantially simultaneous (c) in retarding the stream at this feeding point to allow time for the completion of the reaction, maintainingthe solids in suspension during this time, and (CZ) in separating the spent mixture of reagents from the neutralized oils by mechanicalmeans, and specifically by filtration, without the addition of water.

The essence of my invention may also be given a practical application in a discontinuous process which is thesubst-antial equivaient of the continuous process above de# scribed and in which the steps are (a) to accumulate a batch of the acidified oil (Zi) to treat this batch with a dry powdered alkaline material and a dry powdered absorbent material, added simultaneously (c) to maintain intermixture to the completion of the reaction and (d) to separate the spent reagent from the neutralized oil by mechanical means, specifically by filtration, without the addition of water for washing. Thisk method is much less convenient and desirable than my described continuous process, butprolduces the same final result.V

It is ynot .compatible with the spirit of my invention to washout the spent reagent material and thereaction products with water,

f 0 ither method `7 bymechanicalmeans. Y f

lThe continuous method of neutralizing any absorbed bodies; thereby VitiatingrtheV results produced by my drytreatment. After the complete removal'ofvsolidsyas by filtra# iro tion7 water may be mixed withv the oil with impunity, should'itfloe desiredy to follow'neu'- trali'zation with any aqueous treatment. i n

i l'claim asmy invention: Y y Y n ll. Cllhe-iiiethod ofv neutralizing an acidified oil which comprises: treating saidoil simulL taneously with dry powdered sodium carbonate and l dry powdered diatomaceous earth lcirculating said materials with said oil 'outof and into a body of said oil until reaction is complete, and separating said materials from said oil ley-mechanical means.

2. The method of'neutralizing an acidiiied 'Y oil which comprises: treating said oil simul- 'taneously with dry'v powderedV sodium car.- Vbonate fandY 'dry -Ypowdrered Y diatomaceous earth; circularting said materials with said oil out ofand into abody of said oil until yreaction is complete,A and separating said 'materials from said oil byli-ltration.

rialsfrom said flowv stream. Y

y 3. vrlhe'method of neutralizing an acidified oil whichcomprises :treating said oil simultaneously'with dry powdered sodium carbonate and dry powdered diatomaceous; earth; circulating said materials with said oil out of and into a body of said oil until reaction is complete, andv separating said materials from saidy oilfbyV subsidencefollowed by fil- :manoirl is complete; separating said materials from' said oil by subsidence; adding ai further quantity of dry'powdered absorbent material andseparating said material from said oilby filtration.H f Y Y nous method of neutralizing 5. Thefcontr an acidified oil` which comprises :establishing a flow Vstream of said oil; materially retarding saidV flow stream to form a bodyofsaid oil-g substantially simultaneously feedinginto said'b'ody dry `powdered sodium carbonate and: dry powdered diatomaceous earthycirculatingsaidmaterials with Vsaid oil through "said body untilV reaction is complete', and 'continuously withdrawing astream of'said oil from said body and separating saidmaterials fromA said stream in a spent vcondition an acidiiied oil which comprises z establishing Y a flow stream of said oil; substantiallysimultaneously feeding finto said iiow stream dry y powdered sodium carbonate-and dry powdered diatomaceous earth gf circulating said reaction iscompletdand filteriiig'l said mate- 7: The ycontinuous method ofaneutralizing an acidiiied oil which comprises: establish# Ving a flow stream of said oil; substantially,

simultaneously' feeding vinto said Vflow* lstream dryY powdered .'cso`dium1carloonate and dry powderedV diatomaceous -earth 5A circulating said materials withk said oil inaclosed cycle l until reaction is complete; settlinga material proportion lof saidfmaterials out. ofV said flow stream .and filtering Y'the remainder of sai materials fromV said flow stream.

8. The continuous method of neutralizing f an acidified Voil which comprises: establish-vv ing a ow stream of said oil; substantially simultaneously feeding into saidflow stream dry Y powdered sodium carbonate ,andfY dry.

powdered diatomaceous earth;A circulatingV said oil with said materials in aclosed cycle until reaction is complete; settling a material proportion of said materialsoutof said flow stream; adding a dry. powdered Vabsorbent material to said flowstream; circulating said oil with said Vabsorbent material until the absorptive power of said materialis subst'anfV tially expended, and filtering all soldmatef rials from said flow stream.

lnfwitness that l claim'the"foregoinglj have hereunto subscribed my name this 2ndY dayofJulyAQQQ. i Y.

- Y i- VElli-@fflHARLEY CANNON.

materials with said `oilin a closed cycle until 

